Why Do Bioequivalence Study

A bioequivalence study is a study conducted to show those two different drugs, or two different dosages of the same drug. It absorbed in the same way and produces the same effect on the required site. For general medicinal products, the concept of bioequivalence is important because bioequivalence with the (original) reference medicinal product must be confirmed before a basic product can be approved. Regulatory authorities charge bioequivalence by considering two standards: the speed of absorption and the extent of absorption. If one or both parameters are different in the formulation of a drug, the authorities will determine that the drug is not bioequivalent to the product of origin.

Bioequivalence studies in humans

Bioequivalence study is designed to compare in vivo behavior from a multisource drug to that of the reference medicine. Often, the product to be estimated and the reference product are administered successively to volunteers with an appropriate interval between the two. This interval is chosen so as to ensure the complete elimination of the drug during the first treatment before the supervision of the second treatment. Blood and urine samples are taken just previous to supervision and at appropriate intervals thereafter for the resolve of the active ingredient and one or more metabolites. The pattern of these concentrations over time in each subject of the study provides an indication of how the substance is released by the product to be assessed and its uptake into the body. To compare the two products, concentration curves are drawn in the blood (including plasma or serum) or urine. The results obtained for each subject are subjected to a statistical analysis.

Products under bioequivalence study

Samples of a drug submitted for bioequivalence for registration must be identical to the product being marketed. In addition to the composition and quality characteristics (including stability), the manufacturing methods must be identical to those that will be applied during normal production.

Ideally, samples should be taken from lots produced on an industrial scale. If this is not possible, pilot or small scale production batches may be used provided their size is not less than 10% of that of normal production batches.

It is recommended that the activity and in vitro dissolution characteristics of the product to be evaluated and the reference product be determined before proceeding with the equivalence study. The active ingredient contents of both products should not differ by more than 5%. If the activity of the reference product is more than 5% from the declared quantity, this difference may be consider later to standardize the results of certain dose-related bioavailability parameters.

Educational goals

• Understand the concepts of bioavailability and bioequivalence
• Know when and how to perform bioavailability and bioequivalence studies
• Identify the key points of this type of study
• Discover the usual problems encountered during the implementation of these studies
• Know how to interpret the results and the statistical analyzes
• To be able to apprehend the admissibility, by the regulatory authorities, of the studies carried out.